[087/152] PM / Runtime: Fix pm_runtime_suspended()

From: Greg KH
Date: Wed Jan 05 2011 - 19:45:22 EST

2.6.36-stable review patch. If anyone has any objections, please let us know.


From: Rafael J. Wysocki <rjw@xxxxxxx>

commit f08f5a0add20834d3f3d876dfe08005a5df656db upstream.

There are some situations (e.g. in __pm_generic_call()), where
pm_runtime_suspended() is used to decide whether or not to execute
a device's (system) ->suspend() callback. The callback is not
executed if pm_runtime_suspended() returns true, but it does so
for devices that don't even support runtime PM, because the
power.disable_depth device field is ignored by it. This leads to
problems (i.e. devices are not suspened when they should), so rework
pm_runtime_suspended() so that it returns false if the device's
power.disable_depth field is different from zero.

Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

Documentation/power/runtime_pm.txt | 4 ++--
include/linux/pm_runtime.h | 3 ++-
2 files changed, 4 insertions(+), 3 deletions(-)

--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -336,8 +336,8 @@ drivers/base/power/runtime.c and include

bool pm_runtime_suspended(struct device *dev);
- - return true if the device's runtime PM status is 'suspended', or false
- otherwise
+ - return true if the device's runtime PM status is 'suspended' and its
+ 'power.disable_depth' field is equal to zero, or false otherwise

void pm_runtime_allow(struct device *dev);
- set the power.runtime_auto flag for the device and decrease its usage
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -67,7 +67,8 @@ static inline void device_set_run_wake(s

static inline bool pm_runtime_suspended(struct device *dev)
- return dev->power.runtime_status == RPM_SUSPENDED;
+ return dev->power.runtime_status == RPM_SUSPENDED
+ && !dev->power.disable_depth;

#else /* !CONFIG_PM_RUNTIME */

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/